(1) Field of Invention
The present invention relates to a series of novel silicone ester quaternary silicone polymers useful in softening hair, and fiber and conditioning skin.
Since the compounds of the present invention are high molecular weight silicone polymers, they have a high degree of oxidative stability, even at elevated temperatures. In addition, these compounds are non volatile and unlike many other traditional fatty quaternary compounds are non yellowing when applied to textile substrates and are non irritating to eyes and skin.
The compounds of the present invention are prepared by the reaction of monochloroacetic acid with a pendant hydroxyl group which is present on a silicone polymer, This results in chloro ester which in a subsequent step is reacted with an amine. In a preferred embodiment the hydroxy containing silicone polymer has been alkoxylated with ethylene oxide, propylene oxide or mixtures thereof. The ability to regulate both the type of alkylene oxide and amount of alkylene oxide present in the silicone polymer results in a series of products ranging in water / oil solubility. The technology used to produce the compounds of the present invention is very flexible and allows us to prepare performance tailored molecules for specific applications.
(2) Object of the Invention
It is the object of the present invention to provide a series of novel ester containing quaternary silicone polymers, which are substantive to skin and hair. This substantivity results in superior softening, conditioning and antistatic properties. The presence of the ester functionality results in improved foam properties over the compounds disclosed in the parent application in which this is a continuation in part. The compounds of the present invention contain a fatty portion which is derived from a fatty amine. Incorporation of this type of group into the silicone molecule results in increased solubility in many organic solvents. This ability to marry fatty chemistry with silicone chemistry results in unexpected solubilities and surface active properties. The compounds also contain varying amounts of ethylene oxide and propylene oxide in the molecule. This results in the ability to vary water solubility and introduce an inverse cloud point into the molecule. Inverse cloud point is well known to those skilled in the surfactant art. It is generally found in nonionic surface active agents. It is not found in quaternary compounds. The inverse cloud point is that temperature at which a soluble compound looses it's solubility in water. Inverse cloud point, also called high cloud point, is thought to be associated with the ability of the alkylene oxide chain to hydrogen bond with the water.
It is another objective of the current invention to provide ester containing quaternary silicone polymers which have very low irritation values when applied to skin and eyes. Irritation is a major problem with traditional fatty cationic materials.
Still another object of the present invention is to provide a series of ester containing quaternary silicone polymers which have differing solubilities in water and organic solvents. This is achieved by selection of the hydroxy silicone polymer used as a raw material.
Application of the compounds of the invention can be from solvent, aqueous dispersion or solution, or applied neat in these process. It is anticipated that the effective conditioning concentration of the compound of this invention ranges from 0.1% to 25% by weight.
The silicone polymers, suitable as raw materials, in a preferred embodiment, contain varying amounts of ethylene oxide, propylene oxide or mixtures thereof. The presence of the oxide in the silicone polymer results in compounds with an inverse cloud point. Inverse cloud point phenomenon are well known to those skilled in the art of nonionic surface active agents. The inverse cloud point is defined as a temperature above which the polymer has minimal solubility in water. If heat is applied to an aqueous solution of the nonionic at the inverse cloud point the material will become insoluble, and the solution will turn milky. It is at this point that the polymer has minimal water solubility. Since the product is no longer in solution at above this temperature, it is within this temperature range that the product has maximum substantivity to a fiber. The ability to use temperature to deposit a lubricant, antistat onto a fiber offers a great advantage in cost effectiveness of fiber treatment, and results in less product usage.
(3) Description of the Arts and Practices
Silicone oils (dimethylpolysiloxane) have been known to be active at the surface of plastic, cellulosic and synthetic fibers as well as paper. Despite the fact that they are lubricants that are stable to oxidation, their high cost and lack of durability has made them cost prohibitive in most application areas. Silicone oils need to be emulsified prior to application. This requires high pressure equipment, surface active agents and generally results in a milky emulsion. Emulsions have experienced stability problems both in terms of freeze thaw instability and upon heating. This has resulted in minimal acceptance of them in commercial products.
The low efficiency of silicone oils is due to the fact that the oil is very water insoluble. Emulsions are generally prepared which contain silicone dispersed in micelles. While this method of application is easier for processing, much of the oil stays in the surfactant micelle and never gets deposited on the fiber. That which does deposit on the fiber surface remains there by hydrophobic binding, not ionic bonding. Since the polydimethylsiloxane is not ionically bonded the effect is very transient. The product is removed with one washing.
Fatty quaternary compounds have been known as softeners for many years. They have a much lower molecular weight than the silicone based compounds of the present invention. For this reason, they are much more irritating to skin and eyes than those materials based upon silicone polymers.
Standard fatty quaternary compounds are prepared by quaternization of a tertiary amine with such agents as benzyl chloride or di-methyl sulfate or di-ethyl sulfate or methyl chloride. These materials are relatively inexpensive but offer several key disadvantages. These include yellowing of fabrics, a tendency to build-up upon repeated treatment, and variability in hand (i.e. softness and feel). Standard softeners used are selected from the following classes:
Class #1. Alkyl Imidazoline Quaternary Compounds made from the quaternization of an imidazoline made by reacting diethylenetriamine, and a high molecular weight fatty acid such as stearic acid. The standard quaternizating agents are di-ethyl sulfate, or methyl chloride, or di-methyl sulfate, or methyl chloride or benzyl chloride.
Class #2. Alkyl or dialkyl tertiary amines quaternized with benzyl chloride or di-ethyl sulfate or methyl chloride or di-methyl sulfate.
Class #3. Quaternary compounds of ethoxylated, propoxylated or nonalkoxylated amido amines derived from the reaction of a high molecular weight fatty acid like stearic acid and a polyamine like diethylene triamine. The standard quaternizating agents are di-ethyl sulfate or di-methyl sulfate or methyl chloride or benzyl chloride.
Class #4. Amido amine salts derived from partially acid neutralized amines.
It is known that under certain catalytic conditions, epichlorohydrin reacts with certain alcohols to give an intermediate which can be used to react with tertiary amines to quaternary compounds. U.S. Pat. No. 3,445,440 to Susi (May 1969) and U.S. Pat. No. 3,517,045 to Susi (June 1970) teaches the use of chlorohydroxypropyl ether to alkylate specific tertiary amines which are the reaction product of a primary fatty amine and ethylene or propylene oxide. The compounds are used as antistatic agents in polymeric compositions such as polyolefin. The antistatic properties of these compounds are achieved by the minimization of static charges on the polymer surface. These anti-static materials are incorporated into the polymer melt and are effective by virtue of their insolubility in the molten polymer. The quaternary compounds migrate to the polymer surface and are effective antistatic agents.
U.S. Pat. No. 4,144,122 to Emanuelsson issued Mar. 13, 1979 teaches that tallow alcohol and certain other higher molecular weight non-guerbet alcohols and their alkoxylates can be reacted with epichlorohydrin, then subsequently with tertiary amines to give compounds suitable for paper debonding.
U.S. Pat. No. 4,215,064 to Lindemann et al issued Jul. 29, 1980 teaches that phosphobetaines can be prepared by the reaction of a phosphate or phosphite salt with epichlorohydrin under aqueous conditions. U.S. Pat. No. 4,283,541 to O'Lenick, et al, issued Aug. 11, 1981 teaches the process for the preparation of the phosphobetaines described in Lindemann (4,215,064). None of these patents teach the compounds of the present invention.
U.S. Pat. No. 4,800,077 issued Jan. 1989 to O'Lenick teaches guerbet alcohol quaternary compounds can be prepared by reacting epichlorohydrin with guerbet alcohols then subsequently reacting the intermediate with amines.
None of the above incorporate silicone into the quaternary compound. Consequently, the unique softening and substantivity properties achieved using the compounds of the present invention are not realized with the above technologies.